More black box grief for Pfizer's Chantix as FDA adds alcohol, seizure warnings
- Pfizer's controversial anti-smoking med Chantix (varenicline) decreases alcohol tolerance and increases seizure risk, according to a new FDA safety communication flagged by the WSJ's Ed Silverman.
- In clinical trials, Chantix increased the likelihood of quitting smoking and not resuming smoking for as long as one year, compared with placebo treatment.
- The FDA has issued its latest Chantix advisory after reviewing a case series submitted by Pfizer, as well as cases in the FDA Adverse Event Reporting System (FAERS).
When the FDA examined the FAERS database, it was clear that Chantix decreases alcohol tolerance, which leads to increased drunkenness and unusual or aggressive behavior. Often, the affected patients had no memory of what had happened. In addition, a FAERS review looking closely at the Chantix-seizure connection showed that patients who had no history of seizure disorder had an increased risk of seizure while taking Chantix. And patients who had well-controlled seizure disorder were also at risk. In most cases, the seizures occurred during the first month of Chantix treatment.
There was one area of investigation, where the FDA did not find increased risk—neuropsychiatric side effects. However, the FDA notes that the studies were not exhaustive of all neuropsychiatric side effects.
The FDA warning may be prudent; however, when it comes to making a decision about Chantix therapy, it becomes a risk-benefit analysis. According to the CDC, smoking is responsible for one in five deaths in the U.S.; decreases life expectancy by an average of 10 years and increases mortality three-fold. Many treating physicians would argue that not being able to drink as much alcohol, or having to monitor for seizures, is worth the benefit of decreased risk of early death and disability.